At least part of the mystery of Stonehenge may have now been solved: It was from the outset a monument to the dead.

New radiocarbon dates from human cremation burials among and around the stones on England's Salisbury Plain indicate that the site was used as a cemetery from 3000 B.C. until after the monuments were erected around 2500 B.C., British archaeologists reported Thursday.

What appeared to be the head of a stone mace, a symbol of authority, was found in one grave, the archaeologists said, indicating that this was probably a cemetery for the ruling dynasty responsible for erecting Stonehenge.

"It's now clear that burials were a major component of Stonehenge," said Dr. Mike Parker Pearson, an archaeologist at England's University of Sheffield.

Some scholars have contended that the enigmatic stones, surrounded by a ditch and earthen banks in concentric circles, likely marked a sacred place of healing.

In a teleconference with reporters, Parker Pearson described three burials of burned bones and teeth that were dated in recent weeks. Researchers estimated that up to 240 people were buried there, all as cremation deposits. Other evidence from the British Isles shows that skeletal burials were rare at this time and that cremation was the custom for the elite.

Another Sheffield archaeologist, Andrew Chamberlain, noted one reason to think that the Stonehenge burials were for generations of a single elite family. The clue, he said, is the small number of burials in the earliest period and the larger numbers in later centuries, as offspring would have multiplied.

Given the monumental surroundings, Parker Pearson said, "one has to assume anyone buried there had some good credentials."

The earliest burial to be tested came from a pit at the edge of the stone monuments; it dates to more or less 3000 B.C. The second burial dates to around 2900 B.C. The most recent one is from around the time the first arrangements of stones appeared on the plain, about 2500 B.C. It was previously believed that the site was a burial ground for only a century after 2700 B.C., well before the distinctive large stones were put in place.

Although most of the cremated remains were uncovered decades ago, Parker Pearson said, it is only in recent years that improved methods of radiocarbon dating have made it possible to analyze burned bones.